Peroneal Tendon Subluxation – When Your Tendon Slips Out of Place

By Dr. Carli Hoover, DPM

Peroneal Tendon Subluxation – When Your Tendon Slips Out of Place

You feel a sudden "pop" or snapping sensation on the outside of your ankle. Your ankle feels unstable, and you notice a bump or bulge on the outer ankle that seems to slide in and out of place. These symptoms suggest peroneal tendon subluxation—a condition where the tendons supporting your ankle slip out of their normal groove. If you're experiencing these symptoms in Central Florida, understanding this condition is your first step toward relief and preventing long-term damage.

What Are the Peroneal Tendons?

The peroneal tendons are two strong tissues that run along the outside of your ankle:

Peroneus longus—helps turn your foot outward and stabilizes your ankle
Peroneus brevis—assists with outward foot rotation and ankle stability

These tendons normally sit snugly in a bony groove called the peroneal groove on the outer side of your ankle, held in place by a strong ligament. When subluxation occurs, the tendons slip out of this groove—sometimes partially, sometimes completely—causing pain, instability, and that characteristic "popping" sensation.

Causes: How the Tendon Slips Out

Peroneal tendon subluxation develops through several mechanisms:

Acute Injury

Ankle sprain—forcing your foot inward violently, damaging the retaining ligament The AAOS sprained-ankle page describes that same inward roll as the typical inversion sprain, and notes the outer-ankle soft tissues can tear along with the ligaments when the foot turns hard.
Direct trauma—a blow to the outside of the ankle
Sudden directional change—rapidly rotating your foot while running or playing sports

Structural Factors

Shallow peroneal groove—a anatomical variation that naturally reduces retaining grip
Loose retaining ligament—weakened tissue that fails to hold tendons securely
Repetitive stress—high-impact activities gradually stretching the supporting structures

Chronic Causes

Chronic ankle instability—from previous sprains that damaged stabilizing structures
Intense athletic activity—particularly in football, basketball, and track and field
Improper footwear—shoes that don't provide adequate ankle support

Athletes and active individuals in the Orlando, Altamonte Springs, Longwood, Lake Mary, and Sanford areas frequently experience this injury.

Symptoms: When Your Tendon Feels Like It's Sliding

If you have peroneal tendon subluxation, you'll likely notice:

"Popping" or "snapping" sensation—especially with certain movements or ankle positions
Lateral ankle pain—on the outside of your ankle
Swelling on the outer ankle—often localized to the peroneal groove area
Visible bulge or bump—that seems to move when you move your foot
Ankle instability—feeling like your ankle might give way
Difficulty with athletic activities—particularly sports requiring quick directional changes
Pain with specific movements—especially when rotating your foot outward

Symptoms may come and go depending on activity level and ankle positioning. Some people experience constant discomfort, while others notice symptoms primarily during sports or high-impact activities.

Diagnosis: Seeing the Subluxation

Accurate diagnosis requires both physical examination and imaging. At CFFAI's locations throughout Central Florida, Dr. Carli Hoover uses a comprehensive diagnostic approach:

Physical Examination

We reproduce the subluxation by positioning your ankle in specific ways that make the tendons slip, confirming the diagnosis and assessing severity.

Imaging Studies

Ultrasound—dynamic imaging that shows the tendon's position during movement, perfectly visualizing subluxation
MRI—detailed images of tendon position, retaining ligament integrity, and associated soft tissue damage
X-rays—rule out associated fractures of the peroneal groove or ankle bones

Ultrasound during ankle movement (dynamic ultrasound) is particularly effective for confirming peroneal tendon subluxation.

Treatment Options: From Bracing to Surgical Repair

Conservative Management (Initial Treatment)

For partial subluxation or acute cases, conservative care is the first approach:

Immobilization—boot or splint keeping your ankle in stable position for 2–6 weeks
Anti-inflammatory medications—NSAIDs to reduce pain and swelling
Rest from aggravating activities—avoiding sports and high-impact movement while healing
Physical therapy—strengthening ankle stabilizers and proprioceptive training
Proper bracing—after initial healing, specialized ankle braces prevent re-subluxation during activity

Many patients with mild cases maintain stability with conservative care and bracing.

Surgical Repair

When conservative treatment fails or subluxation is severe and complete:

Retaining ligament repair or reconstruction—tightening or replacing the ligament holding tendons in place
Peroneal groove deepening—increasing the groove's depth to better grip tendons
Tendon relocation—repositioning tendons if necessary

Surgical outcomes are excellent, particularly when performed by experienced surgeons like Dr. Carli Hoover. Recovery involves gradual rehabilitation over 3–6 months.

When to See a Podiatrist

If you experience the snapping, popping, or unstable sensation on your ankle's outside, especially after an ankle injury or during athletic activity, seek evaluation promptly. Early intervention prevents chronic instability and ongoing damage to the tendons.

Getting Back to Full Activity

At Central Florida Foot & Ankle Institute, we're committed to getting you back to the activities you love—whether that's professional athletics, weekend recreation, or simply pain-free daily living.

Call (407) 307-0006 or book at https://floridafai.intakeq.com/booking. Let's restore your ankle stability and get you moving again.

Peroneal Tendon Subluxation – When Your Tendon Slips Out of Place